Plate feed mechanism

ABSTRACT

An improved plate feed mechanism is operable to engage a printing plate in a drawer, to move the printing plate from the drawer to a printing station, and to return the printing plate to the drawer. This plate feed mechanism includes a pair of front plate feed slides which are raised upwardly through a feed stroke to move a first printing plate from the drawer to an intermediate station and to move a second printing plate upwardly from the intermediate station to an inspection station. Simultaneously therewith, a pair of rear plate feed slides move a third printing plate downwardly from the inspection station toward a printing station and move a fourth printing plate from the printing station back to the drawer. Each time a printing plate is removed from the drawer, the drawer is indexed or moved through a distance equal to the thickness of a printing plate to position a next succeeding printing plate for engagement by the front plate feed slides.

United States Patent [1 1 See et a1.

[4 1 Sept. 16, 1975 1 PLATE FEED MECHANISM [73] Assignee: Addressograph Multigraph Corporation, Cleveland, Ohio 22 Filed: Jan. 26, 1973 211 App]. No.: 327,051

[52] US. Cl. 101/56; 101/269; 101/233; 198/225; 214/1 BB; 214/8.5 F; 271/129;

[51] Int. Cl. B41L 47/18 [58] Field of Search 271/34, 35, 2.8 A, 129, 271/112, 114; 214/8.5 F, 1 BB; 101/47-66,

3,480,357 11/1969 Tsuyama et a1 353/115 3,592,463 7/1971 Bonnema et al...... 271/143 3,726,590 4/1973 Kistner et a1. 271/129 Primary Examiner-Edgar S. Burr Assistant Examiner-Wi11iam Pieprz Attorney, Agent, or Firm-Russel1 L. Root; Ray S. Pyle [5 7] ABSTRACT An improved plate feed mechanism is operable to engage a printing plate in a drawer, to move the printing plate from the drawer to a printing station, and to return the printing plate to the drawer. This plate feed mechanism includes a pair of front plate feed slides which are raised upwardly through a feed stroke to move a first printing plate from the drawer to an intermediate station and to move a second printing plate upwardly from the intermediate station to an inspection station. Simultaneously therewith, a pair of rear plate feed slides move a third printing plate downwardly from the inspection station toward a printing station and move a fourth printing plate from the printing station back to the drawer. Each time a printing plate is removed from the drawer, the drawer is indexed or moved through a distance equal to the thickness of a printing plate to position a next succeeding printing plate for engagement by the front plate feed slides.

39 Claims, 22 Drawing Figures PATENTED $5? I 8 i375 Sli-LET 2 UP 9 wk QM ILITI W SEP 161975 if f N 12 2/6 #2 5] 1 5 "*1' H 5 sum 6 GF 9 PATENTEU SEP 1 6 I975 PLATE FEED MECHANISM BACKGROUND The genesis of machine addressing probably is shown in the US. Pat. No. 558,936 issued on Apr. 28, 1896 to Joseph S. Duncan, one of the founders of the business later to become the Addressograph Multigraph Corporation. Slow as it was, it provided accurate addressing from fixed plates.

From such a start, a sophisticated line of business machines, such for example as U.S. Pat. No. 2,359,850, were developed to do repetition printing of addresses and other fixed information from metal plates stored in long storage drawers. These machines are designed for long hard service conditions of large mailing demands.

SUMMARY This invention provides a lower cost addressing machine to meet needs of those not served by the larger commercial machines. It will take a plate from a plate storage drawer and return it to the same drawer. The drawer is advanced one plate thickness as each plate is taken from the drawer and one added back, in order that a machine slide may operate in a fixed path to pick up new plates.

This invention provides a vertical path of plate movement, whereby a plate is picked from the drawer, elevated to an apex position and then switched to a separate decending path. In that descending path the plate is caused to pause in a print station where an impression is created on a form such as a mailing envelope.

This invention is directed to the plate handling portion of the complete machine.

Accordingly, it is an object of this invention to provide a new and improved apparatus for sequentially feeding printing plates from a drawer to a printing station and wherein the apparatus includes a reciprocatable pickup device for engaging a lower edge of a printing plate disposed in the drawer and a drive mechanism for moving the pickup device through a lift stroke to remove the printing plate from the drawer.

Another object of this invention is to provide a new and improved apparatus for feeding printing plates to a printing station from a drawer disposed beneath the printing station and wherein the apparatus includes a first slide assembly for engaging a printing plate disposed in the drawer and for moving the printing plate to a location disposed above the printing station, a second slide assembly for moving the printing plate downwardly to the printing station, and a printing apparatus at the printing station for effecting the transmittal of data from the printing plate to sheet material.

Another object of this invention is to provide a new and improved apparatus for use in sequentially feeding printing plates from a plate holder to an intermediate station and from the intermediate station to a receiving station and wherein the apparatus includes a resiliently deflectable lift finger which extends downwardly from a body and has a nose formed on its lower end to engage a lower edge ofa printing plate in the plate holder and a second resiliently deflectable finger extending upwardly from the body and having a nose for engaging the lower edge ofa printing plate disposed at the intermediate station above the plate holder to move the printing plate from the intermediate station toward the receiving station as a printing plate is moved from the plate holder toward the intermediate station.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a pictorial illustration of a printing apparatus constructed in accordance with the present invention;

FIG. 2 is an elevational view of the printing apparatus of FIG. 1 with a portion of its casing removed;

FIG. 3 is an enlarged sectional view, similar to FIG.

FIG. 4 is a plan view along the line 44 of FIG. 3;

FIG. 5 is an elevational sectional view, taken generally along the line 5-5 of FIG. 4;

FIG. 6 is a schematic elevational view along the line 66 of FIG. 5;

FIG. 7 is a schematic elevational view, generally similar to FIG. 6, but on a smaller scale;

FIG. 8 is a schematic elevational view, taken on a reduced scale along the line 8-8 of FIG. 5;

FIG. 9 is a schematic view, similar to FIG. 5 and taken along the line 9-9 of FIG. 7;

FIG. 10 is a sectional view, generally similar to FIG.

FIG. 11 is a sectional view, generally similar to FIG. 10;

FIG. 12 is a sectional view, generally similar to FIGS. 10 and I1;

FIG. 13 is a sectional view along the line 13l3 of FIG. 6;

FIG. 14 is a sectional view along the line l4l4 of FIG. 6;

FIG. 15 is an enlarged elevational view of a left front plate feed slide;

FIG. 16 is an elevational view along the line I6l6 of F G. 15;

FIG. 17 is a plan view along the line 17-17 of FIG. 15;

FIG. 18 is an enlarged elevational view of a left rear plate feed slide;

FIG. 19 is an elevational view along the line I919 of FIG. 18;

FIG. 20 is a plan view along the line 2020 of FIG. 18;

FIG. 21 is a schematic illustration of a drive mecha nism for moving the front and rear plate feed slides; and

FIG. 22 is a graph depicting movement ofa plate feed slide.

DESCRIPTION OF ONE EMBODIMENT A printing apparatus 10 is shown in FIGS. I4 and includes a sheet material supply hopper 16 in which a plurality of sheet material articles, such as envelopes 18, are stored on edge in an upright orientation. The envelopes 18 are transported one at a time from the hopper 16 along a horizontal path to a printing station 20 by a conveyor assembly 22 (FIG. 4). Printing plates 26 are moved sequentially along a vertical path from a removable drawer 28 to the printing station 20 by an improved plate feed mechanism 32 (FIG. 5). During a printing operation, data is transferred from one of the printing plates 26 to one of the envelopes 18 at the printing station 20. As a next succeeding envelope is moved toward the printing station 20 by the conveyor assembly 22, the printed envelope is discharged through an opening 34 to a tray 36 (FIG. 1 While this is occurring, a next succeeding printing plate is moved toward the printing station 20 and the used printing plate is returned to the drawer 28 by the plate feed mechanism 32. After all of the printing plates 26 have been removed from and returned to the drawer 28 in their original sequence by the plate feed mechanism 32, the drawer 28 may be removed from a holder 42 and returned to a suitable storage cabinet.

The envelopes 18 are stored in the hopper 16 with their face surfaces extending vertically upright and with their lower edge portions disposed in engagement with a support surface 48 (FIG. 4) which slopes downwardly toward a front control panel 52. When an envelope 18 is to be transferred from the hopper 16 to the printing station 20, and intermittent drive assembly 54 is activated by energizing a solenoid 56 for a short time to move a forwardmost one of the envelopes 18 onto a continuously driven conveyor belt 86.

The conveyor belt 86 engages a lower edge of an envelope l8 and transports it toward the printing station 20 with the envelope in an upright position, that is with the opposite face surfaces of the envelope 18 disposed in a substantially vertical orientation.

When the envelope 18 reaches the printing station 20, the leading edge of the envelope is stopped by engagement with a registration nip 100 (FIG. 4) formed by a pair of rollers 102 and 104 in an assembly 106. Engagement of the leading edge of the envelope 18 with the nip 100 registers the envelope longitudinally relative to the printing station 20.

The envelope 18 remains in the upright orientation at the printing station 20 while data is transferred from a printing plate 26 to the envelope. After this printing operation has taken place, the roller 104 is rotated to move the envelope 18 through the opening 34 (FIG. 1 into the tray 36. It should be noted that the assembly 106 can be moved, with the conveyor belt 86, from the retracted position as shown in FIG. 4 to the extended position shown in FIG. 1 to register different portions of an envelope 18 relative to a printing plate 26 at the printing station 20 or center different lengths of envelopes.

The specific construction of the conveyor assembly 22 is more fully disclosed and claimed in US. Application Ser. No. 327,064, filed on Jan. 26, 1973, by J. G. Gardner et a]., and entitled Form Feed and Transport Assembly. It should be understood that the specific construction of the conveyor assembly 22 is not part of the present invention. The conveyor assembly 22 is utilized to transport many different types of sheet material articles, such as phamplets to the printing station 20.

The plate feed mechanism 32 is operable to feed printing plates 26 in sequence upwardly from a pickup station 120 (see FIGS. 5, 6 and 7) to an intermediate station 122 and from the intermediate station to an inspection station 124. After each of the printing plates 26 is raised in turn to the inspection station 124, the printing plate is moved downwardly to the printing station 20 (FIGS. and 8) where it is utilized to transfer data to one of the envelopes l8. Downward movement of the used printing plate 26 is then continued to a return station 126 in the drawer 28.

The plate feed mechanism 32 includes a front plate feed assembly 130 (see FIGS. 7 and 9) and a rear plate feed assembly 132. The front plate feed assembly 130 elevates a printing plate 26 to the intermediate station 122 and simultaneously therewith, moves a preceeding printing platefrom the intermediate station upwardly to the inspection station 124. While the front plate feed assembly moves printing plates upwardly, the rear plate feed assembly 132 moves a printing plate downwardly from the inspection station 124 to the printing station 20 and simultaneously therewith, moves a printing plate downwardly from the printing station to the return station 126.

The front plate feed assembly 130 includes left and right slides 136, 138 (FIG. 7) which engage notches 141 in the lower edge portion 142 of a printing plate 26a in the drawer 28. The slides 136, 138 move vertically upwardly along the tower 134 from the position shown in solid lines in FIG. 7 to the position shown in dashed lines in FIG. 7 to lift the printing plate 26a upwardly from the drawer 28 to the intermediate station 122. Simultaneously with movement of the printing plate 26a to the intermediate station 122, the slides 136, 138 move an immediately preceeding printing plate 26b upwardly from the intermediate station 122 to the inspection station 124.

As the printing plates 26a and 26b are being moved upwardly, preceeding printing plates 26c and 26d (FIG. 8) are moved downwardly by operation of the rear plate feed assembly 132. The rear plate feed assembly 132 includes a pair of slides 152 and 154 which engage an upper edge 158 of the printing plate 260 and are moved vertically downwardly toward the drawer 28 to push the printing plate 260 away from the inspection station 124 toward the printing station 20. As the printing plate 260 is being moved downwardly from the inspection station 124 to the printing station 20, the printing plate 26d is pushed back into its sequential position in the drawer 28 by the slides 152 and 154.

The printing plates 26b, 26c, and 26d are supported at the intermediate station 122, inspection station 124 and printing station 20 by support assemblies 168, and 172 (see FIGS. 5, 6, 10, 11 and 12). The support assembly 168 includes a pair of levers 176, 182 which engage the lower edge of the printing plate 26b at the intermediate station 122. The two levers 176, 182 are of the same construction and are pivotally mounted on a horizontal support shaft 188 adjacent opposite frame members 192, 194 of the tower 134. The support assembly 170 includes a pair of identical levers 198, 200 (see FIGS. 6, 10 and 14) which cooperate with a movable support plate 204 at the inspection station 124. The levers 198, 200 engage stop members 212, 214 (FIGS. 6 and 14) to block rotational movement of the levers about a support shaft 216 under the influence of biasing springs 218, 220.

The support plate 204 is urged into engagement with the levers 198, 200 under the influence of a pair of springs 228, 230 (FIG. 6) disposed on a pivotally mounted support shaft 232. The support plate 204 engages a printing face surface 236 of the printing plate 260 to support the printing plate with the back surface 238 exposed to an operator. Indicia on a printing plate 26 can be read by an operator when the printing plate is at the inspection station 124.

The support assembly 172 at the printing station 20 includes a pair of levers 240, 242 (FIGS. 6, 10 and 13) which are pivotally mounted on axially aligned pins 244, 246 (FIG. 6). The levers 240, 242 are urged into engagement with the lower edge 142 of the printing plate 26d by biasing springs 252, 254 (FIGS. 6 and.l0). The levers 240, 242 urge the printing plate upwardly so that the upper edge 158 of the printing plate 26d is disposed in engagement with a register surface 260 on the lever 198. The lever 200 has a register surface (not shown) which also cooperates with the upper edge of the printing plate 26d.

When the front and rear plate feed assemblies 130, 132 are being operated, the support assemblies 168, 170 and 172 are actuated to enable printing plates to be moved from and to the associated stations 122, 124 and 20. When the front plate feed assembly 130 is operated, the levers 176, 182 are pivoted rearwardly to enable the printing plate 26a to move upwardly past the levers. Once the lower edge 142 of the printing plate 26a has cleared the levers 176 and 182, the levers pivot forwardly. It should be noted that the slides 136, 138 raise the lower edge 142 of the printing plate 26a slightly above the levers 176, 182. Therefore, the printing plate 26a is lowered downwardly onto the levers 176, 182 during a return stroke of the slides 136, 138.

The support assembly 170 at the inspection station 124 is operated from its normal retaining position (FIG. to its actuated or release position (FIG. 11) by initial downward movement of the printing plate 26c under the influence of the slides 152, 154. The support plate 204 is rotated in a counterclockwise direction (as viewed in FIGS. 10 and 1 1) about shaft 232 against the influence of the springs 228 and 230 (FIG. 6). As the printing plate 260 continues to move downwardly, the lower edge 142 of the printing plate slides along the levers 198, 200 to pivot the levers about the shaft 216 against the influence of the spring 218 (see FIG. 11). As the printing plate 261' is being moved away from the inspection station 124, the printing plate 26b is being moved toward the inspection station 124 (see FIG. 1 1 The pivoting movement of the levers 198, 200 by the printing plate 260 moves them out of the way of the printing plate 26b.

The front plate feed assembly 130 moves the printing plate 26h upwardly until it engages a pair of rearwardly sloping cam surfaces 280 formed in the tower frame members 192, 194 (see FIGS. 6 and 11). As this oc curs. the printing plate 26b moves out of a pair of guide tracks 284 formed in the frame members 192, 194 (see FIGS. 6, 11 and 13) so that the printing plate is free to move inwardly or rearwardly under the influence of the cam surfaces 280.

Once the lower edge 142 of the printing plate 26b is moved past the levers 198, 200 the levers are released to pivot forwardly from the position shown in FIG. 11 to the position shown in FIG. 12. At the same time, the support plate 204 is returned to the position shown in FIG. 10 by springs 228 and 230. It should be noted that the lower edge 142 of the printing plate 26b is raised above levers 198 and 200 (see FIG. 12) by the front plate feed assembly 130. Therefore during a return stroke of the front plate feed assembly 130, the printing plate 26b is lowered downwardly from the position shown in FIG. 12 to the position of the printing plate 26c in FIG. 10.

As the printing plate 26c is moved downwardly from the inspection station 124 to the printing station 20, the upper edge 158 of the printing plate 260 is moved past the register surfaces 260 on the levers 198, 200. Once the levers I98, 200 are moved back to their normal positions (see FIG. 12) the register surfaces 260 are disposed vertically above the upper edge 158 of the printing plate 260. As the rear plate feed assembly 132 is moved through a return stroke, the levers 240 and 242 are rocked in a counter-clockwise direction about their support pins 244 and 246 under the influence of the biasing springs 252, 254 to press the lower edge 142 of the printing plate 260 upwardly until the upper edge 158 of the printing plate 260 engages the register surfaces 260 on the levers 198, 200. The overfeeding and return movement of the printing plate 260 insures that it firmly engages the register surfaces 260 on the levers 198 and 200 to properly register the printing plate 260 vertically relative to the printing station 20.

As the printing plates 26 are moved upwardly along the tower 134 from the pickup station to the intermediate station 122, movement of the printing plates is guided by the vertical tracks 284 formed in opposite frame members 192, 194 of the plate tower (see FIGS. 6, 10 and 13). Blocking plates 294, 296 (FIGS. 6 and 10) prevent the feeding of more than one printing plate at a time from the drawer 28 to the guide tracks 284.

The drawer 28 is continuously urged rearwardly by a negator type spring 302 (FIG. 5) which is connected to the bottom of the holder 42 on which the drawer is disposed. A packing assembly 306 cooperates with the printing plates in the drawer 28 to align each printing plate in turn with the guide tracks 284. When the printing plate 26a (FIG. 10) is removed from the drawer 28, the printing surface 236 on the next succeeding printing plate 26e is moved into engagement with the pack ing assembly 306 (FIG. 11) as the drawer is moved rearwardly under the influence of the spring 302.

The packing assembly 306 includes a pair of arms 310, 312 (FIGS. 6 and 10) which extend vertically downwardly into the drawer 28. The arms 310, 312 have front surfaces 316 which engage the printing plates 26 in turn to position the printing plates in vertical alignment with the guide tracks 284. The arms 310, 312 are located by stop members 320, 322 which project inwardly from the opposite frame members 192, 194 (FIG. 6).

The used printing plates 26 are pushed toward the rear of the drawer 28 by packing levers 326, 328 which are pivotally mounted on the shaft 188. The packing levers 326, 328 press the used printing plates rearwardly of a pair of vertical rear guide tracks 332 (FIGS. 10 and 13) along which the printing plates are moved downwardly from the printing station 20.

As a printing plate 26d is moved from the printing station 20 toward the drawer 28 (FIG. 11), the lower edge 142 of the printing plate 26d moves into engagement with rear surfaces 336 of the packing levers 310, 312. Continued downward movement of the printing plate 26d pivots the packing levers 326, 328 forwardly, that is in a clockwise direction as viewed in FIG. 11, away from the immediately preceeding printing plate 26f in the drawer 28. As the printing plate 26d enters the drawer 28, the printing plate 26d is pressed rearwardly of the tracks 332 by the packing levers 326, 328 (FIG. 12).

The front plate feed slides 136, 138 are disposed in vertical tracks 350, 352 (FIG. 13) in the opposite frame members 192, 194. The rear plate feed slides 152, 154 are disposed in vertical tracks 354, 356 in the rear position of the upstanding frame members 192,

The left slide 136 (FIGS. I517) of the front plate feed assembly 13 includes a generally rectangular body 360 which is received in the guide track 350. A transversely extending web 362 is integrally formed with the body 360 and extends outwardly through an opening 364 to the guide track 350 (FIG. 13). A pair of vertically aligned lift fingers 368, 3711 (FIGS. 15 and 16) extend in opposite directions from the web 362. The downwardly extending lift finger 368 is provided with a nose 374 having a horizontal lift surface 376 which engages the bottom edge 142 of a printing plate in the manner shown in FIG. 10. The nose 374 lifts the printing plate 26a upwardly as the slide 136 is raised upwardly along the track 350. A horizontal lift surface 380 (FIGS. 15 and 16) is formed on a nose 382 on the upwardly extending lift finger 3711. The lift surface 38% engages the lower edge 142 of the printing plate 261) and pushes the printing plate 26/; upwardly from the intermediate station 122 to the inspection station 124.

When the slide 136 is moved downwardly through a return stroke, the nose 374 on the lift finger 368 engages the upper edge 158 of the printing plate 26: and resiliently deflects the vertical lift finger 368 rearwardly and then slides down the surface 236 of the printing plate 262. When the lift surface 376 moves below the bottom edge 142 of the printing plate 24w at a notch 141, the natural resilience of the deflected lift finger 368 causes the nose 374 to move the surface 376 into the notch in the printing plate. The notch 141 provides room between the bottom of the drawer 28 and the lower edge 142 of the printing plate 26e to enable the nose 374 to engage the printing plate while it is in the drawer. A vertical stop surface 391) (FIG. 16) is then disposed in abutting engagement with the surface 236 of the printing plate 26 The nose 382 on lift finger 370 is deflected rearwardly by engagement of a cam surface 394 with an upper edge 158 of the printing plate 260 (FIG. 12) as the slide 136 is moved downwardly during a return stroke. As the cam surface 394 engages the upper edge 158 of the printing plate 26a, the resiliently deflectable lift finger 370 is deflected rearwardly of its vertical orientation. During continued downward movement of the slide 136, the nose 382 slides down the printing surface 236 of the printing plate 26a. Once the nose 382 has moved beneath the lower edge 142 of the printing plate 261:, the natural resilience of the lift finger 370 causes the lift finger to return to its normal vertical orientation with the horizontal surface 380 disposed be neath the lower edge 142 of the printing plate 26a at a notch 141.

The slide 136 is advantageously molded as an integral unit of a suitable polymeric material, such as nylon, so that the lift fingers 368 and 3711 will have the requisite resilience to enable them to the deflected by engagement with printing plates during a return stroke of the slide. However, it is contemplated that the slide 136 could be formed of other suitable materials and could be made up of a plurality of interconnected pieces. Al though only the left slide 136 has been shown in FIGS. 15, 16 and 17, it should be understood that the right slide 138 is of the same identical construction, except that it is a mirror image of the slide 136.

The slide 154 (FIGS. 18, 19 and 21)) of the rear plate feed assembly 132 has a rectangular body 4011 which is received in the guide track 354. A pair of pusher fingers 402 and 404 extend in opposite directions from the body 4011 and engage a pair of printing plates to push them downwardly during a feed stroke of the rear plate feed slide 154. The pusher finger 402 includes a cam surface 408 which engages the back surface 238 ofa printing plate at the inspection station 124- to pivot the printing plate and the support plate 2114 in a counterclockwise direction from the position shown in FIG. 10 toward the position shown in FIG. 11 during a feed stroke of the slide 154.

As the slide 154 is moved downwardly from the raised position of FIG. 10, the cam surface 408 moves into abutting engagement with the back surface 238 of the printing plate 260 at the inspection station 124. Continued downward movement of the rear plate feed slide 154 presses the cam surface 408 against the back surface 238 of the printing plate 26c and pivots the printing plate and support plate 204 reareardly. As this occurs, the upper edge 158 of the printing plate 260 moves into abutting engagement with a horizontal pusher surface 412 formed on the bottom of a nose 414 of the pusher finger 402 (see FIGS. 11 and 12). The pusher surface 412 pushes the printing plate 260 downwardly to the position shown in FIG. 12 as the slide 154 moves through a feed stroke.

The downwardly extending pusher finger 404 of the slide 154 is formed with a nose 418 having a horizontal bottom or pusher surface 420 which engages the top edge 158 of a printing plate. The pusher surface 421) pushes a printing plate downwardly from the printing station 20 into the drawer 28.

During a return stroke of the slide 154, the nose 418 on pusher finger 404 must move upwardly past the printing plate 260 which has just been moved to the printing station 21). The nose 418 is moved forwardly during a return stroke to clear the lower edge 142 of a printing plate at the printing station 211. To provide for this movement of nose 418, the pusher finger 404 is resiliently deflectable from its vertical orientation by engagement of a cam surface 424 with the lower edge 142 of the printing plate 26 at the printing station 20. The printing plate 260 is held against movement upwardly from the printing station 20 by engagement with the registration surfaces 260 on the levers 198, 2110.

Although only the slide 154 of the rear plate feed assembly 132 has been shown in FIGS. 18, 19 and 211, it should be understood that the slide 152 is a mirror image of and is constructed in the same manner as the slide 154. Both of the slides 152, 154 are integrally molded of a suitable polymeric material, such as nylon. However, it is contemplated that the slides 152, 154 could be constructed of other materials by method other than molding.

A. drive assembly 4411 for moving the front and rear plate feed slides 136, 138, 152 and 154 through feed and return strokes in unison is illustrated in FIG. 21 in association with the slide 138 of the front plate feed assembly and slide 152 of the rear plate feed assembly 132. The drive assembly 440 includes a crank arm 444 which is driven by main drive motor 446 (FIG. 4) through a suitable gear train 448. The motor 446 is operated at a constant speed and causes the gear train 448 to rotate a drive shaft 452 and crank arm 444 at a constant speed. Rotation of the crank arm 444 through one half of a revolution from an initial position, shown in FIG. 21 in solid lines, to an intermediate position, shown in dashed lines in FIG. 21, moves the slides 138, 152 through a feed stroke (from the position shown in solid lines in FIG. 21 to the position shown in dashed lines in FIG. 21).

Drive forces are transmitted to the slides 138, 152 by a cable 456 which extends from a fixed connection 458 around an idler pulley 4611 and a drive pulley 462 on the crank arm 444. The cable 456 extends from the drive pulley 462 around idler pulleys 466, 468 to a connection 470 on the bottom of the slide 152. The top of the slide 152 is connected with the slide 138 by a cable 474 which extends from a connection 476 at the top of the slide 152 around an idler pulley 478 to a connection 480 at the top of the slide 138. The slide 138 is continuously urged to the lowered position shown in FIG. 21 by an elongated resiliently stretchable coil spring 484 which is connected to the bottom of the slide 138 and extends around an idler pulley 488 to a connection 490.

As the crank arm 444 is rotated from the position shown in dashed lines in FIG. 21 to the position shown in solid lines, the spring 484 pulls the slide 138 downwardly to its lowered position and pulls the slide 152 upwardly to its raised position. As the crank arm 444 is rotated from the position shown in solid lines to the position shown in dashed lines in FIG. 21, the cable 456 pulls the slide 152 downwardly and the slide 138 upwardly through feed strokes against the influence of the spring 484..

Since the crank arm 444 is rotated at a constant speed by the motor 446, the slides 138, 152 are accelerated sinusoidally through feed and return strokes with a movement depicted by a curve 500 in FIG. 22.

It should be noted that the X axis for the curve 500 is the degrees of rotation of the crank arm 44 and that the Y axis is the extend of displacement of the slide 136, 138 between the raised and lowered positions. Of course, the slides 152, 154 move in a similar manner. This sinusoidal movement of the slide 136, 138, 152, 154 results in a gradual acceleration and deceleration of the printing plates 26 to prevent unnecessary bouncing of the printing plates.

Although only the connections between the crank arm 444 and the slide 138 and slide 152 have been shown in FIG. 21, it should be understood that the slide 136 and slide 154 are connected with the crank arm by a cable 510 (FIG. 9) which extends around the pulley 512 to the slide 154. The slide 154 is connected with the slide 136 by a cable 514 in the same manner as in which the slide 152 is connected to the slide 138 by a cable 474. A biasing spring 520 (FIG. 9) continuously urges the slide 136 downwardly in the same manner as in which the biasing spring 484 continuously urges the slide 138 downwardly.

Between operating cycles of the plate feed mechanism 32, a printing assembly 560 (see FIGS. 4 and 5) at the printing station prints on an envelope 18 with one of the printing plates 26. The printing assembly 560 includes a roller platen 562 which is reciprocated from right to left (as viewed in FIG. 4) along a support rod 564 to move an impression roller 566 through a printing stroke across an anvil 570. During the printing stroke, the roller 566 presses an envelope 18 against a ribbon 574, printing plate 26, and anvil 570 to imprint data on the envelope 18 (FIG. 5).

Once the platen 562 reaches the end of its printing stroke (FIG. 4), the printing roller 566 is toggled to a retracted position and the platen is moved through a return stroke during which the roller is spaced from the envelope 18. During this return stroke, the drive roller 104 in the assembly 106 is rotated at a relatively high speed to accelerate the printed envelope away from the printing station 20 through the opening 38 and into the tray 36. As the printed envelope is moved away from the printing station 20, a next succeeding envelope 18 is moved toward the printing station 20 by the conveyor assembly 22. In addition, the plate feed mechanism 32 is activated to move a next succeeding printing plate 26 to the printing station.

The platen 560 is reciprocated back and forth through printing and return strokes by a printing drive assembly 578 (FIG. 4) which is connected with the platen by suitable cables 580. The drive assembly 578 is driven by the main motor 446. Since both the drive assembly 578 and the plate feed mechanism 32 are driven by the motor 446, these two mechanism are maintained in synchronism.

The construction of the printing assembly 560 and drive assembly 578 is more fully described and claimed in copending application Ser. No. 327,052, filed on Jan. 26, 1973, by F. A. Deutsch, and entitled Printing Machine. Although the specific construction of the printing assembly 560 does not, per se, form a part of the present invention, it is believed that the printing as-' sembly disclosed in the aforementioned application is particularly well suited for use in the printing apparatus 10. However, it should be understood that other suitable known printing assemblies could, if desired, be utilized.

Each time the printing platen 562 is moved through a printing stroke, a ribbon indexing assembly 590 is activated to index the ribbon 574 relative to the anvil 570. The ribbon indexing assembly 590 is of a known construction and indexes the ribbon 574 through equal increments each time the assembly is activated. Activation of the ribbon indexing assembly 590 removes ribbon from a supply spool 592.

When the printing apparatus 10 is to be operated, a drawer 28 of the printing plates 26 is removed from a suitable storage location and manually carried to the printing apparatus 10. The holder 42 is then withdrawn by pulling it outwardly against the influence of the spring 302. The drawer 28 is then deposited in the holder 42 with the packing assembly 306 between the back of the drawer and the rearward most printing plate 26. The holder 42 is released and the spring 302 pulls the drawer 28 and holder 42 rearwardly so that the rearward face surface of the innermost printing plate 26 is disposed in abutting engagement with the surfaces 316 on the arms 310 and 312.

A plate feed switch on the control panel 52 is then actuated to activate the plate feed mechanism 32 and lift a first printing plate 26 vertically upwardly from the drawer 28 to the intermediate station 122. When this occurs, the spring 302 moves the drawer 28 and holder 42 rearwardly to position the next succeeding printing plate for engagement by the plate feed mechanism 32. When the plate feed switch on the control panel 52 is again depressed, the plate feed mechanism 32 moves the first printing plate up to the inspection station 124 and the next succeeding printing plate up to the intermediate station 122. When the first printing plate is disposed at the inspection station 124, it is illuminated by a suitable light 598 (FIG. 5) and is clearly visable to an operator of the printing apparatus 10. If the operator does not desire to have this printing plate printed, he may subsequently depress a skip button on the control panel 52 so that the printing assembly 560 is not activated when that printing plate is at the printing station 20.

Assuming that the printing plate at the inspection station 124 is to be utilized to imprint data onto an envelope 18 at the printing station 20, the plate feed mechanism 32 moves the printing plate from the inspection station 124 to the printing station 20 the next time the plate feed button is depressed. When this occurs, automatic operation of the printing apparatus is initiated. During each cycle of operation, a printing plate is lifted from the plate storage drawer 28, started along the vertical path to the printing station 20. Also, on each cycle of operation of the apparatus 10, the conveyor assembly 22 moves an envelope 18 from the storage hopper 16 to the printing station 20. As soon as a printing operation has been performed at the printing station to transfer data from a printing plate 26 to the envelope 18, the envelope is moved further along its horizontal path and through the opening 34 by the assembly 106. At the same time, the used printing plate is moved vertically downwardly from the printing station 20 and returned to the drawer 28 by the plate feed mechanism 32. While one printing plate is being returned to the drawer 28, a next succeeding printing plate is moved to the printing station 20 and another printing plate is removed from the drawer 28.

The printing apparatus 20 includes control circuitry constructed in the manner disclosed and claimed in US. Application Ser. No. 326,920, filed on Jan. 26, 1973, by M. C. Adhikari et al., entitled Printing Apparatus ontrols. Although the controls disclosed in the aforementioned application are believed to be particularly advantageous for use in the printing apparatus 10, it should be understood that other suitable controls could be used and that the present invention is not to be limited to any specific type of controls.

After all of the printing plates in the drawer 28 have been fed to the printing station 20 in turn and returned back to the drawer by the plate feed mechanism 32, the drawer 28 and holder 42 are pulled outwardly against the influence of the spring 302 and the drawer is removed from the holder 42 and returned to a suitable storage location. As the drawer 28 is pulled outwardly, the packing assembly 306 is swung in a clockwise direction about the shaft 188 from the position shown in P16. 10. This rotation of the packing assembly 306 moves the levers 310 and 312 and the packing levers 326, 328 out of the drawer 28. It should be noted that the stop members 320, 322 projectinwardly of the side frames 192, 194 for a relatively short distance (FIG. 6) and are clear of the packing levers 326, 328 so that they are free to swing upwardly and forwardly as the drawer 28 is removed.

What is claimed is:

1. Apparatus for sequentially feeding printing plates from a plate holder to a printing station, said apparatus comprising plate guide means for guiding movement of the printing plates to the printing station, reciprocatable pickup means for engaging a lower edge portion of a first printing plate disposed in the plate holder at a pickup station, cyclically operable drive means for moving said pickup means through a lift stroke to move the first printing plate from the plate holder into engagement with said guide means, said drive means being operable to move said pickup means downwardly through a return stroke and into engagement with a lowermost edge portion of the second printing plate at the pickup station and to thereafter move said pickup means upwardly through a second lift stroke to move the second printing plate from the plate holder to said guide means, said drive means including a drive member, motor means for moving said drive member, and elongated flexible connector means for operatively interconnecting said drive member and said pickup means, said connector means including variable length spring means and cable means connected to said pickup means, said motor means being operable to move said drive member and cable means to alternately increase and decrease the effective length of said spring means during lift and return strokes of said pickup means, and means for sequentially moving the printing plates along said guide means to the printing station.

2. Apparatus as set forth in claim 1 wherein said pickup means includes means for moving the first printing plate relative to said guide means simultaneously with movement of the second printing plate from the plate holder.

3. An apparatus as set forth in claim 1 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of the first printing plate out of the plate holder to position the second printing plate at the pickup station.

4. Apparatus as set forth in claim 1 wherein said pickup means includes a body portion and an elongated flexible lift finger having a transversely extending nose means for engaging the lower edge portion of a printing plate, said flexible lift finger being resiliently deflected in a direction transverse to the direction of movement of said pickup means during the return stroke by engagement of said nose means with the second printing plate.

5. Apparatus as set forth in claim 1 wherein said pickup means includes an elongated flexible lift finger having a transversely protruding end portion which is engageable with a lower edge portion of a printing plate and an elongated flexible pusher finger having a transversely protruding end portion which is engagable with a lower edge portion of another printing plate, said lift and pusher fingers being resiliently deflectable by engagement of their transversely protruding end portions with the first and second printing plates respectively during the return stroke of said pickup means, said pusher finger being operable to push said first printing plate along said guide means simultaneously with a lifting of said second printing plate by said lift finger during a lift stroke of said pickup means.

6. An apparatus as set forth in claim 1 wherein said drive means includes constant speed motor means and transmission means for transmitting drive forces from said constant speed motor means to said pickup means, said transmission means including means for accelerating said pickup means in an upward direction during an initial portion of a lift stroke and decelerating said pickup means during a final portion of the lift stroke and for accelerating said pickup means in a downward direction during an initial portion of a return stroke and decelerating said pickup means during a final portion of the return stroke.

7. An apparatus as set forth in claim 1 wherein said pickup means includes a first member for engaging one end portion of the lower edge portion of a printing plate and a second member for engaging another end portion of the lower edge portion of a printing plate, said drive means including means for reciprocating said first and second members in unison along spaced apart parallel paths during the lift and return strokes of said pickup means.

8. An apparatus for sequentially feeding printing plates from a series of printing plates to a printing station, said apparatus comprising plate holder means holding a series of upright printing plates in a face-toface relationship, said plate holder means including a pair of upstanding side walls and a bottom wall extending between and connected with lower edge portions of said side walls, said bottom wall including surface means for engaging a lower edge portion of each of the printing plates in the series of printing plates, said upstanding side walls having upper edge portions which at least partially define a longitudinally extending opening, guide means for guiding movement of printing plates to the printing station, said guide means including an open end portion disposed above said plate holder means in alignment with one of the printing plates in the series of printing plates, pickup means for removing each of the printing plates in turn from said plate holder means, said pickup means being movable along an upstanding path between a retracted position disposed above the upper edge portions of the side walls of said plate holder means and an extended position in which at least a portion of said pickup means is disposed between the upstanding side walls of said plate holder means, said pickup means including means for engaging the lower edge portion of said one of the printing plates which is in alignment with the open end portion of said guide means when said pickup means is in the extended position, drive means for moving said pickup means downwardly along the upstanding path from the retracted position through the opening to the extended position to move said pickup means into engagement with the lower edge portion of the one of the printing plates which is in alignment with the open end portion of said guide means and for moving said pickup means upwardly along the upstanding path of lift the engaged printing plate of the series of printing plates upwardly through the opening into engagement with said guide means and along said guide means to a position above the series of printing plates in said plate holder means, means for moving said bottom wall of said plate holder means along a second path extending transversely to said upstanding path to position a next succeeding printing plate in the series of printing plates in alignment with the open end portion of said guide means upon removal of said engaged printing plate from the series of printing plates, and means for sequentially moving printing plates along said guide means to the printing station.

9. Apparatus as set forth in claim 8 wherein said pickup means includes means for moving a printing plate relative to said guide means simultaneously with movement of the engaged printing plate from the plate holder.

10. An apparatus as set forth in claim 8 wherein said means for moving said bottom wall of said plate holder means includes means for moving said bottom wall of said plate holder means through a distance along said second path which is at least as great as the thickness of a printing plate upon movement of the engaged printing plate out of said plate holder to position the next succeeding printing plate in alignment with the open end portion of said guide means.

11. Apparatus as set forth in claim 8 wherein said pickup means includes a body portion and an elongated flexible lift finger having a transversely extending nose means for engaging the lower edge portion of a printing plate, said flexible lift finger being resiliently deflected in a direction transverse to the upstanding path by engagement of said nose means with the upper edge portion of a printing plate as said pickup means moves downwardly from the retracted position toward the extended position.

12. Apparatus as set forth in claim 8 wherein said pickup means includes an elongated flexible lift finger having a transversely protruding end portion which is engagable with a lower edge portion of a printing plate and an elongated flexible pusher finger having a transversely protruding end portion which is engagable with a lower edge portion of another printing plate, said lift and pusher fingers being resiliently deflectable by engagement of their transversely protruding end portions with printing plates during the downward movement of said pickup means from the retracted position to the extended position, said pusher finger being operable to push a printing plate along said guide means simultaneously with a lifting of another printing plate by said lift finger during upward movement of said pickup means from the extended position toward the retracted position.

13. An apparatus as set forth in claim 8 wherein said drive means includes constant speed motor means and transmission means for transmitting drive forces from said constant speed motor means to said pickup means, said transmission means including means for accelerating said pickup means in an upward direction during initial upward movement of said pickup means from the extended position toward the retracted position and decelerating said pickup means during a final portion of the movement of said pickup means from the extended position to the retracted position and for accelerating said pickup means in a downward direction during an initial portion of the downward movement of said pickup means from the retracted position toward the extended position and decelerating said pickup means during a final portion of the movement of said pickup means from the retracted position to the extended position.

14. An apparatus as set forth in claim 8 wherein said pickup means includes a first member for engaging one end portion of the lower edge portion of a printing plate and a second member for engaging another end portion of the lower edge portion of a printing plate when said pickup means is in the extended position, said drive means including means for moving said first and second members in unison along spaced apart parallel paths during movement of said pickup means between the extended and retracted positions.

15. An apparatus for feeding individual printing plates of a series of printing plates to a printing station, said apparatus comprising plate holder means for holding the series of printing plates with each printing plate in an upright on-edge orientation, said plate holder means including wall means for at least partially defining a compartment to receive the series of printing plates, means at the printing station for effecting a transmittal of data from a printing plate to sheet material, and plate transfer means for removing each of the on-edge printing plates in turn from said compartment in said plate holder means, for moving the printing plates to the printing station, and for returning the printing plates to said compartment in said plate holder means, said plate transfer means including first surface means for engaging a lower edge portion of a printing plate disposed in an on-edge orientation in said compartment, drive means for moving said first surface means and the engaged printing plate upwardly away from said compartment to a position in which the engaged printing plate and said first surface means are disposed above the upper edge portions of the series of printing plates in said compartment, means for retaining a printing plate in an upright orientation during at least a portion of the movement of the printing plate away from the printing station, and second surface means for engaging an upper edge portion of an upright printing plate during at least a part of its movement away from the printing station, said drive means being operable to move said second surface means toward said compartment to push the upper edge portion of a printing plate engaged by said second surface means toward said compartment.

16. An apparatus as set forth in claim 15 wherein said plate transfer means further includes first guide means for guiding upward movement of a printing plate along a first path length and second guide means for guiding downward movement of a printing plate along a second path length which is spaced apart from said first path length, said first surface means being movable by said drive means to effect upward movement of a printing plate along said first path length. said second surface means being movable by said drive means to effect downward movement of a printing plate along said second path length.

17. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate to a location disposed above the printing station, second slide means for moving the printing plate downwardly to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder from which it was removed by said first slide means by continuing the downward movement of the printing plate from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station, said first slide means includes first surface means for engaging a first printing plate disposed in the plate holder and second surface means for engaging a second printing plate disposed above the plate holder to enable said first slide means to simultaneously move the first and second printing plates upwardly, said second slide means including third surface means for engaging a third printing plate and fourth surface means for engaging a fourth printing plate disposed below the third printing plate to enable said second slide means to simultaneously move the third and fourth printing plates downwardly.

18. An apparatus as set forth in claim 17 further including drive means for moving said first slide means upwardly and for simultaneously therewith moving said second slide means downwardly to raise the first and second printing plates while lowering the third and fourth printing plates.

19. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship, first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate upwardly along said first and second supports to a location disposed above the printing station, second slide means for moving the printing plate downwardly along said first and second supports to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder from which it was removed by said first slide means by continuing the downward movement of the printing plate from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station, said first slide means including a first slide member movably mounted on said first support and a second slide member movably mounted on said second support, first guide means for guiding movement of a printing plate from the plate holder along said first and second supports toward the location disposed above the printing station, and drive means for reciprocating said first and second slide members up and down in unison through feed and return strokes along said first and second supports respectively to move a printing plate engaged by said first and second slide members upwardly during a feed stroke and to move said first and second slide members into engagement with a printing plate disposed in the plate holder during a return stroke.

20. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate along a first upright path to a location disposed above the printing station, said first slide means including a first slide member movable along said first path from a first position in which said first slide member is at least partially disposed within the plate holder to a position in which said first slide member is disposed above the plate holder to move the printing plate upwardly from the plate holder, second slide means for moving the printing plate downwardly to the printing station along a second upright path which is spaced apart from and vertically coextensive with the first path, and printing means at the printing station for effecting the transmit tal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder form which it was removed by said first slide means by continuing the downward movement of the printing plate along said second path from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station.

2ll. An apparatus as set forth in claim 20 further including first guide means for guiding movement of the printing plate along said first path as the printing plate is moved upwardly under the influence of said first slide means, said first path having an entrance adjacent to the plate holder, second guide means for guiding movement of the printing plate along said second path as the printing plate is moved downwardly from the printing station under the influence of said second slide means, said second path having an outlet adjacent to the plate holder and spaced apart from the entrance to said first path, and spacer means for spacing apart printing plates in the plate holder by a distance which is at least as great as the distance between the entrance to said first path and the outlet from said second path.

22. An apparatus as set forth in claim 20 further including drive means for effecting operation of said first slide means to move one printing plate from the plate holder and for effecting operation of said second slide means to return another printing plate to the plate holder after removal of the one printing plate from the plate holder and before removal of a succeeding printing plate from the plate holder by said first slide means.

23. An apparatus as set forth in claim 20 further including drive means for effecting upward movement of said first slide means from a lowered position and for simultaneously thereiwth effecting downward movement of said second slide means to enable one printing plate to be moved upwardly from the plate holder simultaneously with movement of another printing plate downwardly toward the printing station.

24. An apparatus as set forth in claim 20 further including guide means for guiding movement of the printing plates along said first and second paths to the printing station, said first slide means including means on said first slide member for engaging a lower edge portion of a printing plate disposed in the plate holder at a pickup station, and cyclically operable drive means for moving said first slide member through a lift stroke to move an engaged printing plate from the plate holder into engagement with said guide means.

25. An apparatus as set forth in claim 24 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of a printing plate out of the plate holder to position a next succeeding printing plate at the pickup station.

26. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station and returning the printing plates to the plate holder, said apparatus comprising first slide means for engaging a lower edge portion of a first printing plate disposed in the plate holder with a face surface of the first printing plate facing in one direction, drive means for moving said first slide means upwardly along a first upright path to lift the first printing plate from the plate holder and to move the first printing plate upwardly to a location disposed above the printing station with the face surface of the first printing plate facing in the one direction, said first slide means including a first plurality of slide members movable along said first upright path, second slide means for engaging an upper edge portion of the first printing plate, said drive means being connected with said second slide means and operable to move said second slide means downwardly along a second upright path which is spaced apart from and vertically coextensive with said first upright path to move the first printing plate to the printing station with the face surface of the first printing plate facing in the one direction, said second slide means including a second plurality of slide members movable along said second upright path, and printing means at said printing station for effecting a trans mittal of data from the printing plate to sheet material with the face surface of the printing plate facing in the one direction, said drive means being operable to move said second slide means downwardly to move the first printing plate from the printing station to the plate holder with the face surface of the first printing plate facing in the one direction.

27. An apparatus as set forth in claim 26 wherein said drive means includes means for moving said first slide means into engagement with a lower edge portion of a second printing plate after movement of the first printing plate to a location above the printing station and for moving said first slide means upwardly to lift the second printing plate from the plate holder simultaneously with downward movement of the second slide means as the first printing plate is moving downwardly to the plate holder.

28. An apparatus as set forth in claim 27 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of the first printing plate from the plate holder to position the second printing plate for engagement by the first slide means, and spacer means for maintaining a space between printing plates in the plate holder to provide space for the return of a printing plate to the plate holder bysaid second slide means.

29. Apparatus for sequentially feeding printing plates from a plate holder and returning the printing plates to the plate holder, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship with each other, plate raising means for sequentially raising each of the printing plates in turn from the plate holder to an upper station disposed at a location above the plate holder, said plate raising means including first slide means movably mounted on said first support and second slide means movably mounted on said second support for simulta neously engaging the lower edge portion of a printing plate at locations adjacent to opposite end portions of the printing plate, first guide means for guiding move ment of a printing plate from the plate holder along said first and second supports toward the upper station, drive means for reciprocating said first and second slide means up and down in unison through feed and return strokes along said first and second supports respectively to lift a printing plate engaged by said first and second slide means from the plate holder toward the upper station during a feed stroke and to move said first and second slide means into engagement with a printing plate disposed in the plate holder during a return stroke, plate lowering means for sequentially moving each of the printing plates in turn away from the upper station and into the plate holder, said plate lowering means including third slide means movably mounted on said first support and fourth slide means movably mounted on said second support for simultaneously engaging upper edge portions of a printing plate at locations adjacent to opposite end portions of the printing plate, second guide means for guiding downward movement of a printing plate away from the upper station along said first and second supports to the plate holder, said drive means including means for reciprocating said third and fourth slide means up and down through feed and return strokes along said first and second supports respectively to push a printing plate engaged by said third and fourth slide means downwardly into the plate holder during a feed stroke and to move said third and fourth slide means into engagement with a printing plate during a return stroke and means for effecting movement of said first and second slide means through feed and return strokes contemporaneously with movement of said third and fourth slide means through feed and return strokes to lift a printing plate upwardly away from the plate holder as a printing plate is pushed downwardly toward the plate holder.

30. An apparatus as set forth in claim 29 wherein said first and second slide means each include first and second flexible lift fingers, first nose means projecting transversely outwardly from said first lift finger for engaging the lower edge portion of a printing plate disposed in the plate holder, second nose means projecting transversely outwardly from said second lift finger for engaging the lower edge portion of another printing plate disposed above the plate holder, said first drive means being operable to press said first nose means downwardly against an upper edge portion of the printing plate in the plate holder to resiliently flex said first lift finger transversely of the printing plate in the plate holder during a return stroke and to press said second nose means downwardly against an upper edge portion of the other printing plate disposed above the plate holder to resiliently flex said second lift finger transversely of the other printing plate during the same return stroke to enable said first and second nose portions to move downwardly along the associated printing plates.

31. Apparatus as set forth in claim 29 further includ ing spacer means for holding adjacent printing plates in the plate holder apart by a distance which is at least as great as the distance between said first and second guide means.

32. An apparatus as set forth in claim 29 wherein said drive means includes flexible cable means connected with each of said slide means and crank arm means for pulling and releasing said cable means to effect movement of each of said slide means in unison.

33. An apparatus for use in sequentially feeding printing plates along a support member from a plate holder to an intermediate station and from the intermediate station to a receiving station, said apparatus comprising body means for moving downwardly through a feed stroke and upwardly through a return stroke along the support member, a first resiliently deflectable lift finger extending downwardly from said body means, first nose means formed on a lower end portion of said first lift finger for engaging an upper edge portion of a first printing plate in the plate holder and deflecting said first lift finger transversely outwardly from the first printing plate as said body means is moved downwardly through a return stroke, for engaging a lower edge portion of the first printing plate at the end of a return stroke, and for raising the first printing plate from the plate holder toward the intermediate station as said body means is moved upwardly through a feed stroke, a second resilient deflectable lift finger extending up wardly from said body means, second nose means formed on an upper end portion of said second lift finger for engaging an upper edge portion of a second printing plate at the intermediate station and deflecting said second lift finger transversely outwardly from the second printing plate at the intermediate station as said body means is moved downwardly through a return stroke, for engaging a lower edge portion of the second printing plate at the intermediate station at the end of a return stroke, and for raising the second printing plate from the intermediate station toward the receiving station as said body means is moved upwardly through a feed stroke.

34. An apparatus as set forth in claim 33 wherein said first nose means includes first cam surface means extending transversely to a longitudinal axis of said first lift finger for camming said first lift finger outwardly as said first nose means is moved into engagement with the upper edge portion of the first printing plate, and said second nose means includes a second cam surface means extending transversely to a longitudinal axis of said second lift finger for camming said second lift finger outwardly as said second nose means is moved into engagement with the upper edge portion of the second printing plate.

35. An apparatus as set forth in claim 34 wherein said first nose means further includes first lift surface means extending transversely to said first cam surface means for engaging the lower edge portion of the first printing plate, and said second nose means further includes second lift surface means extending transversely to said second cam surface means for engaging the lower edge portion of the second printing plate.

36. An apparatus as set forth in claim 35 wherein said first and second lift fingers are disposed with their longitudinal axes extending parallel to each other when said first and second nose means are spaced from said first and second printing plates.

37. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship, first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate to a location disposed above the printing station, second slide means for moving the printing plate downwardly to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said first slide means including a first slide member movably mounted on said first support and a second slide member movably mounted on said second support, first guide means for guiding movement of a printing plate from the plate holder along said first and second supports toward the location disposed above the printing station, and drive means for reciprocating said first and second slide members up and down in unison through feed and return strokes along said first and second supports respectively to move a printing plate engaged by said first and second slide members upwardly during a feed stroke and to move said first and second slide members into engagement with a printing plate disposed in the plate holder during a return stroke, said second slide means including a third slide member movably mounted on said first support and a fourth slide member movably mounted on said second support, said drive means including means for reciprocating said third and fourth slide members up and down through feed and return strokes along said first and second supports respectively to push a printing plate engaged by said third and fourth slide members downwardly into the plate holder during a feed stroke and to move said third and fourth slide members into engagement with a printing plate during a return stroke.

38. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath 

1. Apparatus for sequentially feeding printing plates from a plate holder to a printing station, said apparatus comprising plate guide means for guiding movement of the printing plates to the printing station, reciprocatable pickup means for engaging a lower edge portion of a first printing plate disposed in the plate holder at a pickup station, cyclically operable drive means for moving said pickup means through a lift stroke to move the first printing plate from the plate holder into engagement with said guide means, said drive means being operable to move said pickup means downwardly through a return stroke and into engagement with a lowermost edge portion of the second printing plate at the pickup sTation and to thereafter move said pickup means upwardly through a second lift stroke to move the second printing plate from the plate holder to said guide means, said drive means including a drive member, motor means for moving said drive member, and elongated flexible connector means for operatively interconnecting said drive member and said pickup means, said connector means including variable length spring means and cable means connected to said pickup means, said motor means being operable to move said drive member and cable means to alternately increase and decrease the effective length of said spring means during lift and return strokes of said pickup means, and means for sequentially moving the printing plates along said guide means to the printing station.
 2. Apparatus as set forth in claim 1 wherein said pickup means includes means for moving the first printing plate relative to said guide means simultaneously with movement of the second printing plate from the plate holder.
 3. An apparatus as set forth in claim 1 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of the first printing plate out of the plate holder to position the second printing plate at the pickup station.
 4. Apparatus as set forth in claim 1 wherein said pickup means includes a body portion and an elongated flexible lift finger having a transversely extending nose means for engaging the lower edge portion of a printing plate, said flexible lift finger being resiliently deflected in a direction transverse to the direction of movement of said pickup means during the return stroke by engagement of said nose means with the second printing plate.
 5. Apparatus as set forth in claim 1 wherein said pickup means includes an elongated flexible lift finger having a transversely protruding end portion which is engageable with a lower edge portion of a printing plate and an elongated flexible pusher finger having a transversely protruding end portion which is engagable with a lower edge portion of another printing plate, said lift and pusher fingers being resiliently deflectable by engagement of their transversely protruding end portions with the first and second printing plates respectively during the return stroke of said pickup means, said pusher finger being operable to push said first printing plate along said guide means simultaneously with a lifting of said second printing plate by said lift finger during a lift stroke of said pickup means.
 6. An apparatus as set forth in claim 1 wherein said drive means includes constant speed motor means and transmission means for transmitting drive forces from said constant speed motor means to said pickup means, said transmission means including means for accelerating said pickup means in an upward direction during an initial portion of a lift stroke and decelerating said pickup means during a final portion of the lift stroke and for accelerating said pickup means in a downward direction during an initial portion of a return stroke and decelerating said pickup means during a final portion of the return stroke.
 7. An apparatus as set forth in claim 1 wherein said pickup means includes a first member for engaging one end portion of the lower edge portion of a printing plate and a second member for engaging another end portion of the lower edge portion of a printing plate, said drive means including means for reciprocating said first and second members in unison along spaced apart parallel paths during the lift and return strokes of said pickup means.
 8. An apparatus for sequentially feeding printing plates from a series of printing plates to a printing station, said apparatus comprising plate holder means holding a series of upright printing plates in a face-to-face relationship, said plate holder means including a pair of upstanding side walls and a bottom wall extending between and connected with lower edge portions of said side walls, said bottom wall including surface means for engaging a lower edge portion of each of the printing plates in the series of printing plates, said upstanding side walls having upper edge portions which at least partially define a longitudinally extending opening, guide means for guiding movement of printing plates to the printing station, said guide means including an open end portion disposed above said plate holder means in alignment with one of the printing plates in the series of printing plates, pickup means for removing each of the printing plates in turn from said plate holder means, said pickup means being movable along an upstanding path between a retracted position disposed above the upper edge portions of the side walls of said plate holder means and an extended position in which at least a portion of said pickup means is disposed between the upstanding side walls of said plate holder means, said pickup means including means for engaging the lower edge portion of said one of the printing plates which is in alignment with the open end portion of said guide means when said pickup means is in the extended position, drive means for moving said pickup means downwardly along the upstanding path from the retracted position through the opening to the extended position to move said pickup means into engagement with the lower edge portion of the one of the printing plates which is in alignment with the open end portion of said guide means and for moving said pickup means upwardly along the upstanding path of lift the engaged printing plate of the series of printing plates upwardly through the opening into engagement with said guide means and along said guide means to a position above the series of printing plates in said plate holder means, means for moving said bottom wall of said plate holder means along a second path extending transversely to said upstanding path to position a next succeeding printing plate in the series of printing plates in alignment with the open end portion of said guide means upon removal of said engaged printing plate from the series of printing plates, and means for sequentially moving printing plates along said guide means to the printing station.
 9. Apparatus as set forth in claim 8 wherein said pickup means includes means for moving a printing plate relative to said guide means simultaneously with movement of the engaged printing plate from the plate holder.
 10. An apparatus as set forth in claim 8 wherein said means for moving said bottom wall of said plate holder means includes means for moving said bottom wall of said plate holder means through a distance along said second path which is at least as great as the thickness of a printing plate upon movement of the engaged printing plate out of said plate holder to position the next succeeding printing plate in alignment with the open end portion of said guide means.
 11. Apparatus as set forth in claim 8 wherein said pickup means includes a body portion and an elongated flexible lift finger having a transversely extending nose means for engaging the lower edge portion of a printing plate, said flexible lift finger being resiliently deflected in a direction transverse to the upstanding path by engagement of said nose means with the upper edge portion of a printing plate as said pickup means moves downwardly from the retracted position toward the extended position.
 12. Apparatus as set forth in claim 8 wherein said pickup means includes an elongated flexible lift finger having a transversely protruding end portion which is engagable with a lower edge portion of a printing plate and an elongated flexible pusher finger having a transversely protruding end portion which is engagable with a lower edge portion of another printing plate, said lift and pusher fingers being resiliently deflectable by engagement of their transversely protruding end portions with printing plates during the downward movement of said pickup means from the retracted position to the extended position, said pusher finger being opErable to push a printing plate along said guide means simultaneously with a lifting of another printing plate by said lift finger during upward movement of said pickup means from the extended position toward the retracted position.
 13. An apparatus as set forth in claim 8 wherein said drive means includes constant speed motor means and transmission means for transmitting drive forces from said constant speed motor means to said pickup means, said transmission means including means for accelerating said pickup means in an upward direction during initial upward movement of said pickup means from the extended position toward the retracted position and decelerating said pickup means during a final portion of the movement of said pickup means from the extended position to the retracted position and for accelerating said pickup means in a downward direction during an initial portion of the downward movement of said pickup means from the retracted position toward the extended position and decelerating said pickup means during a final portion of the movement of said pickup means from the retracted position to the extended position.
 14. An apparatus as set forth in claim 8 wherein said pickup means includes a first member for engaging one end portion of the lower edge portion of a printing plate and a second member for engaging another end portion of the lower edge portion of a printing plate when said pickup means is in the extended position, said drive means including means for moving said first and second members in unison along spaced apart parallel paths during movement of said pickup means between the extended and retracted positions.
 15. An apparatus for feeding individual printing plates of a series of printing plates to a printing station, said apparatus comprising plate holder means for holding the series of printing plates with each printing plate in an upright on-edge orientation, said plate holder means including wall means for at least partially defining a compartment to receive the series of printing plates, means at the printing station for effecting a transmittal of data from a printing plate to sheet material, and plate transfer means for removing each of the on-edge printing plates in turn from said compartment in said plate holder means, for moving the printing plates to the printing station, and for returning the printing plates to said compartment in said plate holder means, said plate transfer means including first surface means for engaging a lower edge portion of a printing plate disposed in an on-edge orientation in said compartment, drive means for moving said first surface means and the engaged printing plate upwardly away from said compartment to a position in which the engaged printing plate and said first surface means are disposed above the upper edge portions of the series of printing plates in said compartment, means for retaining a printing plate in an upright orientation during at least a portion of the movement of the printing plate away from the printing station, and second surface means for engaging an upper edge portion of an upright printing plate during at least a part of its movement away from the printing station, said drive means being operable to move said second surface means toward said compartment to push the upper edge portion of a printing plate engaged by said second surface means toward said compartment.
 16. An apparatus as set forth in claim 15 wherein said plate transfer means further includes first guide means for guiding upward movement of a printing plate along a first path length and second guide means for guiding downward movement of a printing plate along a second path length which is spaced apart from said first path length, said first surface means being movable by said drive means to effect upward movement of a printing plate along said first path length, said second surface means being movable by said drive means to effect downward movement of a printing plate along said second path length.
 17. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate to a location disposed above the printing station, second slide means for moving the printing plate downwardly to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder from which it was removed by said first slide means by continuing the downward movement of the printing plate from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station, said first slide means includes first surface means for engaging a first printing plate disposed in the plate holder and second surface means for engaging a second printing plate disposed above the plate holder to enable said first slide means to simultaneously move the first and second printing plates upwardly, said second slide means including third surface means for engaging a third printing plate and fourth surface means for engaging a fourth printing plate disposed below the third printing plate to enable said second slide means to simultaneously move the third and fourth printing plates downwardly.
 18. An apparatus as set forth in claim 17 further including drive means for moving said first slide means upwardly and for simultaneously therewith moving said second slide means downwardly to raise the first and second printing plates while lowering the third and fourth printing plates.
 19. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship, first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate upwardly along said first and second supports to a location disposed above the printing station, second slide means for moving the printing plate downwardly along said first and second supports to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder from which it was removed by said first slide means by continuing the downward movement of the printing plate from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station, said first slide means including a first slide member movably mounted on said first support and a second slide member movably mounted on said second support, first guide means for guiding movement of a printing plate from the plate holder along said first and second supports toward the location disposed above the printing station, and drive means for reciprocating said first and second slide members up and down in unison through feed and return strokes along said first and second supports respectively to move a printing plate engaged by said first and second slide members upwardly during a feed stroke and to move said first and second slide members into engagement with a printing plate disposed in the plate holder during a return stroke.
 20. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate along a first upright path to a location disposed above the printing station, said first slide means including a first slide member movable along said first path from a first position in which said first slide member is at least partially disposed within the plate holder to a position in which said first slide member is disposed above the plate holder to move the printing plate upwardly from the plate holder, second slide means for moving the printing plate downwardly to the printing station along a second upright path which is spaced apart from and vertically coextensive with the first path, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said second slide means including means for returning the printing plate to the same plate holder form which it was removed by said first slide means by continuing the downward movement of the printing plate along said second path from the printing station to the plate holder after the transmittal of data to the sheet material at the printing station.
 21. An apparatus as set forth in claim 20 further including first guide means for guiding movement of the printing plate along said first path as the printing plate is moved upwardly under the influence of said first slide means, said first path having an entrance adjacent to the plate holder, second guide means for guiding movement of the printing plate along said second path as the printing plate is moved downwardly from the printing station under the influence of said second slide means, said second path having an outlet adjacent to the plate holder and spaced apart from the entrance to said first path, and spacer means for spacing apart printing plates in the plate holder by a distance which is at least as great as the distance between the entrance to said first path and the outlet from said second path.
 22. An apparatus as set forth in claim 20 further including drive means for effecting operation of said first slide means to move one printing plate from the plate holder and for effecting operation of said second slide means to return another printing plate to the plate holder after removal of the one printing plate from the plate holder and before removal of a succeeding printing plate from the plate holder by said first slide means.
 23. An apparatus as set forth in claim 20 further including drive means for effecting upward movement of said first slide means from a lowered position and for simultaneously thereiwth effecting downward movement of said second slide means to enable one printing plate to be moved upwardly from the plate holder simultaneously with movement of another printing plate downwardly toward the printing station.
 24. An apparatus as set forth in claim 20 further including guide means for guiding movement of the printing plates along said first and second paths to the printing station, said first slide means including means on said first slide member for engaging a lower edge portion of a printing plate disposed in the plate holder at a pickup station, and cyclically operable drive means for moving said first slide member through a lift stroke to move an engaged printing plate from the plate holder into engagement with said guide means.
 25. An apparatus as set forth in claim 24 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of a printing plate out of the plate holder to position a next succeeding printing plate at the pickup station.
 26. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station and returning the printing plates to the plate holder, said apparatus comprising first slide means for engaging a lower edge portion of a first printing plate disposed in the plate holder with a face surface of the first printing plate facing in one direction, drive means for moving said first slide means upwardly along a first upright path to lift the first printing plate from the plate holder and to move the first printing plate upwardly to a location disposed above the printing station with the face suRface of the first printing plate facing in the one direction, said first slide means including a first plurality of slide members movable along said first upright path, second slide means for engaging an upper edge portion of the first printing plate, said drive means being connected with said second slide means and operable to move said second slide means downwardly along a second upright path which is spaced apart from and vertically coextensive with said first upright path to move the first printing plate to the printing station with the face surface of the first printing plate facing in the one direction, said second slide means including a second plurality of slide members movable along said second upright path, and printing means at said printing station for effecting a transmittal of data from the printing plate to sheet material with the face surface of the printing plate facing in the one direction, said drive means being operable to move said second slide means downwardly to move the first printing plate from the printing station to the plate holder with the face surface of the first printing plate facing in the one direction.
 27. An apparatus as set forth in claim 26 wherein said drive means includes means for moving said first slide means into engagement with a lower edge portion of a second printing plate after movement of the first printing plate to a location above the printing station and for moving said first slide means upwardly to lift the second printing plate from the plate holder simultaneously with downward movement of the second slide means as the first printing plate is moving downwardly to the plate holder.
 28. An apparatus as set forth in claim 27 further including means for moving the plate holder through a distance which is at least as great as the thickness of a printing plate upon movement of the first printing plate from the plate holder to position the second printing plate for engagement by the first slide means, and spacer means for maintaining a space between printing plates in the plate holder to provide space for the return of a printing plate to the plate holder by said second slide means.
 29. Apparatus for sequentially feeding printing plates from a plate holder and returning the printing plates to the plate holder, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship with each other, plate raising means for sequentially raising each of the printing plates in turn from the plate holder to an upper station disposed at a location above the plate holder, said plate raising means including first slide means movably mounted on said first support and second slide means movably mounted on said second support for simultaneously engaging the lower edge portion of a printing plate at locations adjacent to opposite end portions of the printing plate, first guide means for guiding movement of a printing plate from the plate holder along said first and second supports toward the upper station, drive means for reciprocating said first and second slide means up and down in unison through feed and return strokes along said first and second supports respectively to lift a printing plate engaged by said first and second slide means from the plate holder toward the upper station during a feed stroke and to move said first and second slide means into engagement with a printing plate disposed in the plate holder during a return stroke, plate lowering means for sequentially moving each of the printing plates in turn away from the upper station and into the plate holder, said plate lowering means including third slide means movably mounted on said first support and fourth slide means movably mounted on said second support for simultaneously engaging upper edge portions of a printing plate at locations adjacent to opposite end portions of the printing plate, second guide means for guiding downward movement of a printing plate awAy from the upper station along said first and second supports to the plate holder, said drive means including means for reciprocating said third and fourth slide means up and down through feed and return strokes along said first and second supports respectively to push a printing plate engaged by said third and fourth slide means downwardly into the plate holder during a feed stroke and to move said third and fourth slide means into engagement with a printing plate during a return stroke and means for effecting movement of said first and second slide means through feed and return strokes contemporaneously with movement of said third and fourth slide means through feed and return strokes to lift a printing plate upwardly away from the plate holder as a printing plate is pushed downwardly toward the plate holder.
 30. An apparatus as set forth in claim 29 wherein said first and second slide means each include first and second flexible lift fingers, first nose means projecting transversely outwardly from said first lift finger for engaging the lower edge portion of a printing plate disposed in the plate holder, second nose means projecting transversely outwardly from said second lift finger for engaging the lower edge portion of another printing plate disposed above the plate holder, said first drive means being operable to press said first nose means downwardly against an upper edge portion of the printing plate in the plate holder to resiliently flex said first lift finger transversely of the printing plate in the plate holder during a return stroke and to press said second nose means downwardly against an upper edge portion of the other printing plate disposed above the plate holder to resiliently flex said second lift finger transversely of the other printing plate during the same return stroke to enable said first and second nose portions to move downwardly along the associated printing plates.
 31. Apparatus as set forth in claim 29 further including spacer means for holding adjacent printing plates in the plate holder apart by a distance which is at least as great as the distance between said first and second guide means.
 32. An apparatus as set forth in claim 29 wherein said drive means includes flexible cable means connected with each of said slide means and crank arm means for pulling and releasing said cable means to effect movement of each of said slide means in unison.
 33. An apparatus for use in sequentially feeding printing plates along a support member from a plate holder to an intermediate station and from the intermediate station to a receiving station, said apparatus comprising body means for moving downwardly through a feed stroke and upwardly through a return stroke along the support member, a first resiliently deflectable lift finger extending downwardly from said body means, first nose means formed on a lower end portion of said first lift finger for engaging an upper edge portion of a first printing plate in the plate holder and deflecting said first lift finger transversely outwardly from the first printing plate as said body means is moved downwardly through a return stroke, for engaging a lower edge portion of the first printing plate at the end of a return stroke, and for raising the first printing plate from the plate holder toward the intermediate station as said body means is moved upwardly through a feed stroke, a second resilient deflectable lift finger extending upwardly from said body means, second nose means formed on an upper end portion of said second lift finger for engaging an upper edge portion of a second printing plate at the intermediate station and deflecting said second lift finger transversely outwardly from the second printing plate at the intermediate station as said body means is moved downwardly through a return stroke, for engaging a lower edge portion of the second printing plate at the intermediate station at the end of a return stroke, and for raising the second printing plate from the intermediate station toward the receiving station as said body means is moved upwardly through a feed stroke.
 34. An apparatus as set forth in claim 33 wherein said first nose means includes first cam surface means extending transversely to a longitudinal axis of said first lift finger for camming said first lift finger outwardly as said first nose means is moved into engagement with the upper edge portion of the first printing plate, and said second nose means includes a second cam surface means extending transversely to a longitudinal axis of said second lift finger for camming said second lift finger outwardly as said second nose means is moved into engagement with the upper edge portion of the second printing plate.
 35. An apparatus as set forth in claim 34 wherein said first nose means further includes first lift surface means extending transversely to said first cam surface means for engaging the lower edge portion of the first printing plate, and said second nose means further includes second lift surface means extending transversely to said second cam surface means for engaging the lower edge portion of the second printing plate.
 36. An apparatus as set forth in claim 35 wherein said first and second lift fingers are disposed with their longitudinal axes extending parallel to each other when said first and second nose means are spaced from said first and second printing plates.
 37. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising a base, first and second supports disposed on opposite sides of the plate holder and extending upwardly from said base in a spaced apart relationship, first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate to a location disposed above the printing station, second slide means for moving the printing plate downwardly to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said first slide means including a first slide member movably mounted on said first support and a second slide member movably mounted on said second support, first guide means for guiding movement of a printing plate from the plate holder along said first and second supports toward the location disposed above the printing station, and drive means for reciprocating said first and second slide members up and down in unison through feed and return strokes along said first and second supports respectively to move a printing plate engaged by said first and second slide members upwardly during a feed stroke and to move said first and second slide members into engagement with a printing plate disposed in the plate holder during a return stroke, said second slide means including a third slide member movably mounted on said first support and a fourth slide member movably mounted on said second support, said drive means including means for reciprocating said third and fourth slide members up and down through feed and return strokes along said first and second supports respectively to push a printing plate engaged by said third and fourth slide members downwardly into the plate holder during a feed stroke and to move said third and fourth slide members into engagement with a printing plate during a return stroke.
 38. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station, said apparatus comprising first slide means for engaging a printing plate disposed in the plate holder and for moving the printing plate to a location disposed above the printing station, second slide means for moving the printing plate downwardly to the printing station, and printing means at the printing station for effecting the transmittal of data from the printing plate to sheet material, said first slide means including a body, means for moving said body downwardly through a feed stroke and upwardly through a return Stroke, a first resiliently deflectable lift finger extending downwardly from said body, first nose means formed on a lower end portion of said first lift finger for camming engagement with an upper edge portion of a first printing plate in the plate holder and deflecting said first lift finger transversely outwardly from the first printing plate as said body is moved downwardly through a return stroke, for engaging a lower edge portion of the first printing plate at the end of return stroke, and raising the first printing plate from the plate holder as said body is moved upwardly through a feed stroke, a second resiliently deflectable lift finger extending upwardly from said body, second nose means formed on an upper end portion of said second lift finger for camming engagement with an upper edge portion of a second printing plate previously lifted by said first lift finger and deflecting said second lift finger transversely outwardly from the second printing plate as said body is moved downwardly through a return stroke, for engaging a lower edge portion of the second printing plate at the end of a return stroke, and for raising the second printing plate as said body is moved upwardly through a feed stroke.
 39. An apparatus for feeding printing plates to a printing station from a plate holder disposed beneath the printing station and returning the printing plates to the plate holder, said apparatus comprising first slide means for engaging a lower edge portion of a first printing plate disposed in the plate holder with a face surface of the first printing plate facing in one direction, said first slide means including a body portion and an elongated flexible lift finger having a transversely extending nose means for engaging the lower edge portion of a printing plate, said flexible lift finger being resiliently deflectable in a direction transverse to the direction of movement of said first slide means by engagement of said nose means with a printing plate as said nose means is moved toward the lower edge portion of the plate, drive means for moving said first slide means to lift the first printing plate from the plate holder and to move the first printing plate upwardly to a location disposed above the printing station with the face surface of the first printing plate facing in the one direction, second slide means for engaging an upper edge portion of the first printing plate, said drive means being connected with said second slide means and operable to move said second slide means downwardly to move the first printing plate to the printing station with the face surface of the first printing plate facing in the one direction, and printing means at said printing station for effecting a transmittal of data from the printing plate to sheet material with the face surface of the printing plate facing in the one direction, said drive means being operable to move said second slide means downwardly to move the first printing plate from the printing station to the plate holder with the face surface of the first printing plate facing in the one direction. 